It's amazing what we can accomplish on the go these days. Our phones have turned into quite the indispensible tool for knitters. They can be stitch counters, can give us access to Ravelry, organizer our projects, pattern keepers and now a knitting chart designer. If you're looking to chart your original knitting design you no longer have to be strapped to your computer. Little Knitter allows you to chart knitting patterns with various symbols at an endless number of gauges. You just use your finger to draw on the screen. You can set it to draw or to erase. Sometimes this can be frustrating because it is too easy to erase your work.
It's a great tool when you're on the go. Granted I'm not an experienced designer, but I was trying to chart an idea I had for a unicorn yarn over pattern. It was nice to have a little sketch pad to work with when I was away from my computer, but as others have found, the touch screen just isn't sensitive enough to be able to do your design with enough fixed control. Lots of mistakes happen. I found using an old palm stylus was helpful.
I wouldn't rely on it for professional projects, but it works in a pinch. You can find it in the Google Play Market.